This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Melanoma vaccines have been associated with major regressions in 3-6% of patients with advanced measurable disease. This provides proof-of-principle of the potential for clinical benefit with melanoma vaccines. However, negative results have been obtained in several phase III clinical trials with some melanoma vaccines. On the other hand, subgroup analyses from at least two of those trials suggest the possibility of benefit in participant subsets. The UVA experience with multipeptide vaccines includes the induction of antitumor immunity in a majority of participants, clinical outcomes for participants treated in the adjuvant setting that exceed predicted outcomes, and clinical tumor regressions in 5-10% of participants treated with vaccines in the setting of advanced metastatic disease. Dramatic regressions of melanoma have been induced with several other immune therapies, including high-dose interleukin-2 (FDA approved for advanced melanoma), anti-CTLA4 antibody, and adoptive T cell therapy, with reported objective response rates of 17%, 13%, and 51%, respectively, and with complete response (CR) rates in the range of 4-7%. Results with these therapies provide further proof-of-principle for the therapeutic potential of immune therapy in melanoma. Unfortunately, the toxicities for all three therapies limit participant eligibility;so less toxic immune therapies with vaccines have a role, especially in the adjuvant setting. The only FDA-approved adjuvant therapy for patients with resected high-risk melanoma is high-dose, systemic interferon alpha. However, the most recent pooled analysis of interferon alpha therapy highlights the questionable survival advantage even of that therapy, for patients in the adjuvant setting. Thus, there is a critical need for additional new therapies for melanoma, both for adjuvant therapy of high-risk resected melanoma and for therapy of patients who are not candidates for, or fail, other therapies in the setting of advanced disease. It is generally agreed that one mechanism to improve the immunologic outcomes of vaccine therapy is to optimize T cell trafficking to the tumor site. CXCR3 is the chemokine receptor on T cells which directs them to sites of inflammation by following the chemokine gradient. The ligands for CXCR3 (CXCL9 (MIG), CXCL10 (IP-10) and CXCL11 (I-TAC)) are known to be induced by interferon gamma (IFN- )13,14. This protocol proposes administering peptide vaccine to activate tumor antigen-specific CD8+ T cells expressing CXCR3, followed by intratumoral interferon gamma to increase CXCR3 ligands (CXCL9-11) at the tumor site and recruit the CXCR3+ T cells. While there is also the potential for clinical benefit for participants receiving the vaccine in combination with intratumoral interferon gamma (Actimmune, interferon gamma-1b), this current study is not powered to test clinical outcomes. The primary goals of the proposed work are to assess the safety of the combination of peptide vaccine and intratumoral interferon gamma and to assess the immunologic outcomes at the tumor site.